package com.inspur.security.cbb3.kms.utils;

import javax.servlet.http.HttpServletRequest;

/**
 * @author: lijunchang
 * @Description: IP工具类
 * @Date: 2020/10/10
 */
public class IpUtil {
    private static final String UNKNOWN_IP = "unknown";
    private static final String IP_SEPARATOR = ",";

    /**
     * 获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址,
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值
     *
     * @param request request
     * @return ip       客户IP
     */
    public static String getRemoteHost(HttpServletRequest request) {
        if (request == null) {
            return UNKNOWN_IP;
        }
        String ip = request.getHeader("x-forwarded-for");
        if (ip != null && ip.length() != 0 && !UNKNOWN_IP.equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            if (ip.indexOf(IP_SEPARATOR) != -1) {
                ip = ip.split(IP_SEPARATOR)[0];
            }
        }
        if (ip == null || ip.length() == 0 || UNKNOWN_IP.equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN_IP.equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Forwarded-For");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN_IP.equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN_IP.equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }

        if (ip == null || ip.length() == 0 || UNKNOWN_IP.equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }

        return "0:0:0:0:0:0:0:1".equals(ip) ? "127.0.0.1" : ip;
    }

}
